/*
 * Copyright 2020 The CodeWorld Authors. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const onObjectPropertyChange = (object, property, callback) => {
  if (!object._propertyChangeHandlers) {
    object._propertyChangeHandlers = {};
  }

  if (!object._propertyChangeHandlers[property]) {
    object._propertyChangeHandlers[property] = [];

    let value = object[property];

    Object.defineProperty(object, property, {
      get() {
        return value;
      },
      set(newValue) {
        value = newValue;

        object._propertyChangeHandlers[property].forEach((handler) =>
          handler()
        );
      },
    });
  }

  object._propertyChangeHandlers[property].push(callback);
};

export { onObjectPropertyChange };
